'use strict'
const path = require('path')
const fs = require('graceful-fs')
const pathExists = require('../path-exists').pathExists
/**
* Function that returns two types of paths, one relative to symlink, and one
* relative to the current working directory. Checks if path is absolute or
* relative. If the path is relative, this function checks if the path is
* relative to symlink or relative to current working directory. This is an
* initiative to find a smarter `srcpath` to supply when building symlinks.
* This allows you to determine which path to use out of one of three possible
* types of source paths. The first is an absolute path. This is detected by
* `path.isAbsolute()`. When an absolute path is provided, it is checked to
* see if it exists. If it does it's used, if not an error is returned
* (callback)/ thrown (sync). The other two options for `srcpath` are a
* relative url. By default Node's `fs.symlink` works by creating a symlink
* using `dstpath` and expects the `srcpath` to be relative to the newly
* created symlink. If you provide a `srcpath` that does not exist on the file
* system it results in a broken symlink. To minimize this, the function
* checks to see if the 'relative to symlink' source file exists, and if it
* does it will use it. If it does not, it checks if there's a file that
* exists that is relative to the current working directory, if does its used.
* This preserves the expectations of the original fs.symlink spec and adds
* the ability to pass in `relative to current working direcotry` paths.
*/
function symlinkPaths (srcpath, dstpath, callback) {
if (path.isAbsolute(srcpath)) {
return fs.lstat(srcpath, (err) => {
if (err) {
err.message = err.message.replace('lstat', 'ensureSymlink')
return callback(err)
}
return callback(null, {
'toCwd': srcpath,
'toDst': srcpath
})
})
} else {
const dstdir = path.dirname(dstpath)
const relativeToDst = path.join(dstdir, srcpath)
return pathExists(relativeToDst, (err, exists) => {
if (err) return callback(err)
if (exists) {
return callback(null, {
'toCwd': relativeToDst,
'toDst': srcpath
})
} else {
return fs.lstat(srcpath, (err) => {
if (err) {
err.message = err.message.replace('lstat', 'ensureSymlink')
return callback(err)
}
return callback(null, {
'toCwd': srcpath,
'toDst': path.relative(dstdir, srcpath)
})
})
}
})
}
}
function symlinkPathsSync (srcpath, dstpath) {
let exists
if (path.isAbsolute(srcpath)) {
exists = fs.existsSync(srcpath)
if (!exists) throw new Error('absolute srcpath does not exist')
return {
'toCwd': srcpath,
'toDst': srcpath
}
} else {
const dstdir = path.dirname(dstpath)
const relativeToDst = path.join(dstdir, srcpath)
exists = fs.existsSync(relativeToDst)
if (exists) {
return {
'toCwd': relativeToDst,
'toDst': srcpath
}
} else {
exists = fs.existsSync(srcpath)
if (!exists) throw new Error('relative srcpath does not exist')
return {
'toCwd': srcpath,
'toDst': path.relative(dstdir, srcpath)
}
}
}
}
module.exports = {
symlinkPaths,
symlinkPathsSync
}